The present invention relates generally to cigarette packaging machines and, more particularly, to a system and method for visually inspecting cigarette packages during the fabrication process.
In cigarette manufacturing, quality control has become a matter of increasing attention. Poor packaging (i.e., packaging which does not conform with predetermined quality requirements) detracts from consumer perceptions of the quality of the packaged goods. Perfectly good items are routinely returned for refund and disposal if they are poorly packaged. On-line inspection during manufacture is one way of controlling packaging non-conformities. In an effort to enhance the on-line quality control capabilities of their production machines, many companies have turned to machine vision techniques wherein cameras are used to allow for inspection of the production process.
In the field of cigarette packaging, conventional vision inspection machines focused on inspecting the cigarette packages after the packages have already been formed. In U.S. Pat. No. 5,101,609, issued to Cook, a vision inspection system is disclosed in which a cigarette packaging machine is modified to include an inspection indexing wheel. The inspection indexing wheel is positioned at a post-construction location along the manufacturing process at which the cigarette packages have already been fully constructed. Such systems are wasteful of packaging material and make the recovery of product more difficult. In those instances where a manufacturing machine is repeatedly producing non-conforming packages, these conventional vision inspection systems, such as the one described in Cook, do not assist the manufacturer in identifying where in the fabrication process correction is needed.
There exists a need for a vision inspection system which inspects cigarette packages during the actual fabrication process.
The present invention seeks to overcome the above-identified deficiencies of the prior art by providing a system and method of detecting non-conforming cigarette packages during the actual fabrication process. According to exemplary embodiments, a digital camera is placed in close proximity to the blank feeding and folding turret area of a cigarette packaging machine assembly. At a location where the cigarette package is partially constructed, the camera captures a digital image of three sections of the pack blank, namely the dust flaps and the inside front panel. The output of the camera is used to visually inspect the pack blank for mis-folded or partially or completely missing dust flaps and a reversed pack blank. The captured image is transferred to a processor which compares the pixel value of the three sections of the pack blank to a predetermined pixel value. If the comparison indicates that the pixel value of any of the three sections does not equal the predetermined pixel value which means that one or more of the dust flaps are either mis-folded or partially/completely missing or that the blank is reversed, the cigarette package is registered as a non-conforming item. Visually inspecting the blank prior to completion of the cigarette package allows for the cigarettes within the non-conforming package to be more easily recycled and aids in diagnosing problems in the actual cigarette packaging process.